RC Columns Strengthened by Steel Jacket
RC Columns Strengthened by Steel Jacket
(OP)
Hello guys;
I have a steel building of 4 floors with concrete columns. We decided to use circular plates around the concrete columns at the connection location (Please See attached) due to the high loads on the end steel beams.
Is there Any good reference for the design of this steel jacketing?. This would be so much appreciated guys :)
I have a steel building of 4 floors with concrete columns. We decided to use circular plates around the concrete columns at the connection location (Please See attached) due to the high loads on the end steel beams.
Is there Any good reference for the design of this steel jacketing?. This would be so much appreciated guys :)






RE: RC Columns Strengthened by Steel Jacket
Brian C Potter, PE
Simple Supports - Back at it again with the engineering blog.
RE: RC Columns Strengthened by Steel Jacket
RE: RC Columns Strengthened by Steel Jacket
It would also be difficult to get the sleeve fitted to the column without some gap in between them.
Suggested approximate quick design check: Take half of the sleeve height, half of the diameter, assume it pinned at the ends, and check bending with the web tension force applied to it.
It might also be possible to come up with designs that used U-bolts to bolt around the column.
RE: RC Columns Strengthened by Steel Jacket
RE: RC Columns Strengthened by Steel Jacket
RE: RC Columns Strengthened by Steel Jacket
Can the beams be made pin supported at the columns?
Probably need the shear anchors if this thing is to be post installed. That, or some kind of adhesive.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: RC Columns Strengthened by Steel Jacket
[Can the columns be concrete-encased steel columns? This would eliminate the beam/girder-to-column connection issues. Can the entire superstructure be cast-in-place concrete?]
Unfortunately, It can not
KootK:
[Are the concrete columns new or existing? Will they be in place prior to the steel showing up?]
They are new, cast in place columns.
KootK
[Can the beams be made pin supported at the columns?]
No, they are moment connection
RE: RC Columns Strengthened by Steel Jacket
RE: RC Columns Strengthened by Steel Jacket
What is the project goal that necessitates this? Are these moment frame beams? Cantilevers? As noted, there are a ton of great reasons not to create the moment connections. If we understand the intent here, we may be able provide more/better help.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: RC Columns Strengthened by Steel Jacket
RE: RC Columns Strengthened by Steel Jacket
Yes.those are moment frames. Ver. Bracing cannot be added for lateral stability. I tried to convince my manager to use steel columns instead of concrete ones to avoid the breakout problems but based on what he said it cant be done due to the project buudget.
Sail3
All I can do for those sleeves is to assume half the sleeve as a simply supported member and check it for bending due to tension and bearing. I have no idea how the bonding between the steel and the concrete would work or what extra analysis should be done here
RE: RC Columns Strengthened by Steel Jacket
Is your manager aware of the issues this will cause during construction? It will be very expensive to constantly switch between concrete and steel crews to build this as they go up the building.
If they're basing their cost solely on typical unit costs, they'll be in for a real treat once someone bids this and they realize how much it actually costs.
RE: RC Columns Strengthened by Steel Jacket
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: RC Columns Strengthened by Steel Jacket
Why not instead of a jacket, use an embedded steel plate with 90 degree hooked bars welded to it? Something like that could be made as big as you needed it to be, really. Fabricating a plate to match the curvature of the column would be a hassle but it's light-years ahead of the difficulties involved in this steel jacket idea.
If you can't get something like that to work, I think you're better off re-examining your framing rather than looking into weird, untried connection ideas.
Brian C Potter, PE
Simple Supports - Back at it again with the engineering blog.